Constant velocity joints (CV joints) are common components in vehicles. Constant velocity joints are often employed where transmission of a constant velocity rotary motion is desired or required. CV joints are typically greased or otherwise lubricated for the life of the component. The joints are preferably sealed to retain the grease or lubricant inside the joint while keeping contaminants and foreign matter, such as water and dirt, out of the joint. Moreover, a sealing boot, which may be made of rubber, thermoplastic, silicone material, or the like usually encloses portions of the CV joints (such as an open end). Additionally, the opposite end of the joint may also be enclosed with an internal cover to close off the CV joint from contaminants.
During operation, a CV joint may create excess internal pressures in the inner chamber of the joint. This function can prevent undesirable pressure build-up during operation of the joint that could damage or compromise components such as the sealing boot. In such instances, it is often desirable to vent pressurized gases from the chamber of the joint to the outer atmosphere to reduce the internal pressure and temperature of the joint. Consequently, many CV joints include a vent.
Vent designs generally must strike a compromise between designs that are either generally permissive or generally restrictive to flow through the vents. While vents incorporating simple configurations generally freely allow venting of gases to and from the joint chamber, such designs necessarily also allow intrusion of water or other external contaminants. On the other hand, vents incorporating relatively complex features may offer more resistance to water and other external contaminants, but may restrict venting of gases to and from the joint chamber.
Accordingly, there is a need for a vent for a CV joint that allows for proper venting of the joint chamber with the external atmosphere, improved sealing of the joint chamber against exterior contaminants, and increased resistance to clogs from joint lubricant.